The present invention relates to devices kown as tranquillizers for use ina conduit to obtain a fluid flow having a regular speed profile.
Tranquillizers are generally mounted in conduits to regulate the flow profile of fluids upstream from a flow meter. Two types of turbulence interfere with flow meter measurements. First, flow speeds may be asymetrically distributed across a planar section perpendicular to the flow. Such asymmetry may be caused, for example, by an elbow in the conduit or by the shutter of a half-closed valve, for example a wedge gate valve. For a flow measuring device such as a Woltmann meter, this type of asymmetrical flow causes a lateral reaction onthe rotor pivot, prematurely wearing the meter as well as causing measurement errors. Another type of turbulence is vortices coaxial to the conduit. These can arise spontaneously or after the fluid has passed an obstacle. This substantially affects the meter rotor speed and hence the accuracy of flow measurements. Either type of turbulence will cause the other, so the two are typically found together. One way of dealing with such turbulences is by using, upstream of the meter, a tranquillizer having a section which flares out to a cylindrical chamber of a diameter greater than that of the conduit. This type of tranquillizer is effective against asymetrical flow distributions, but vortexes are barely attenuated.
Another solution, so-called honeycomb tranquillizers, are excellent for eliminating vortices, but have little effect on asymetrical flow distributions. The axial speed of the portion of fluid flowing through a honeycomb passage is affected relatively little. In addition, it is costly to fabricate and mount honeycomb tranquillizers in conduits.
The present invention has for an object therefore, an improved tranquillizer for regulating a fluid flow profile.